Can a bowl of oatmeal help lower your cholesterol? How about a handful of walnuts or an avocado? A few simple tweaks to your diet — like these, along with exercise and other heart-healthy habits — might help you lower your cholesterol.

Oatmeal contains soluble fiber, which reduces your low-density lipoprotein (LDL), the "bad" cholesterol. Soluble fiber is also found in such foods as kidney beans, apples, pears, barley and prunes.

Soluble fiber can reduce the absorption of cholesterol into your bloodstream. Five to 10 grams or more of soluble fiber a day decreases your total and LDL cholesterol. Eating 1 1/2 cups of cooked oatmeal provides 6 grams of fiber. If you add fruit, such as bananas, you'll add about 4 more grams of fiber. To mix it up a little, try steel-cut oatmeal or cold cereal made with oatmeal or oat bran.

Eating fatty fish can be heart healthy because of its high levels of omega-3 fatty acids, which can reduce your blood pressure and risk of developing blood clots. In people who have already had heart attacks, fish oil — or omega-3 fatty acids — may reduce the risk of sudden death.

Although omega-3 fatty acids don't affect LDL levels, because of their other heart benefits, the American Heart Association recommends eating at least two servings of fish a week. The highest levels of omega-3 fatty acids are in:

Mackerel

Lake trout

Herring

Sardines

Albacore tuna

Salmon

Halibut

You should bake or grill the fish to avoid adding unhealthy fats. If you don't like fish, you can also get small amounts of omega-3 fatty acids from foods such as ground flaxseed or canola oil.

You can take an omega-3 or fish oil supplement to get some of the benefits, but you won't get other nutrients in fish, such as selenium. If you decide to take a supplement, talk to your doctor about how much you should take.

Eating about a handful (1.5 ounces, or 42.5 grams) a day of most nuts, such as almonds, hazelnuts, peanuts, pecans, some pine nuts, pistachio nuts and walnuts, may reduce your risk of heart disease. Make sure the nuts you eat aren't salted or coated with sugar.

All nuts are high in calories, so a handful will do. To avoid eating too many nuts and gaining weight, replace foods high in saturated fat with nuts. For example, instead of using cheese, meat or croutons in your salad, add a handful of walnuts or almonds.

Avocados are a potent source of nutrients as well as monounsaturated fatty acids (MUFAs). According to a recent study, adding an avocado a day to a heart-healthy diet can help improve LDL levels in people who are overweight or obese.

People tend to be most familiar with avocados in guacamole, which usually is eaten with high-fat corn chips. Try adding avocado slices to salads and sandwiches or eating them as a side dish. Also try guacamole with raw cut vegetables, such as cucumber slices.

Replacing saturated fats, such as those found in meats, with MUFAs are part of what makes the Mediterranean diet heart healthy.

Another good source of MUFAs is olive oil.

Try using about 2 tablespoons (23 grams) of olive oil a day in place of other fats in your diet to get its heart-healthy benefits. To add olive oil to your diet, you can saute vegetables in it, add it to a marinade or mix it with vinegar as a salad dressing. You can also use olive oil as a substitute for butter when basting meat or as a dip for bread.

Both avocados and olive oil are high in calories, so don't eat more than the recommended amount.

Foods are available that have been fortified with sterols or stanols — substances found in plants that help block the absorption of cholesterol.

Some margarines, orange juice and yogurt drinks come with added plant sterols and can help reduce LDL cholesterol by 5 to 15 percent. The amount of daily plant sterols needed for results is at least 2 grams — which equals about two 8-ounce (237-milliliter) servings of plant sterol-fortified orange juice a day.

It's not clear whether food with plant sterols or stanols reduce your risk of heart attack or stroke, although experts assume that foods that reduce cholesterol do reduce the risk. Plant sterols or stanols don't appear to affect levels of triglycerides or of high-density lipoprotein (HDL), the "good" cholesterol.

Whey protein, which is one of two proteins in dairy products — the other is casein — may account for many of the health benefits attributed to dairy. Studies have shown that whey protein given as a supplement lowers both LDL and total cholesterol.

You can find whey protein powders in health food stores and some grocery stores. Follow the package directions for how to use them.

For any of these foods to provide their benefit, you need to make other changes to your diet and lifestyle.

Although some fats are healthy, you need to limit the saturated and trans fats you eat. Saturated fats, like those in meat, butter, cheese and other full-fat dairy products, and some oils, raise your total cholesterol. Trans fats, often used in margarines and store-bought cookies, crackers and cakes, are particularly bad for your cholesterol levels. Trans fats raise LDL cholesterol, and lower high-density lipoprotein (HDL), the "good" cholesterol.

Food labels report the content of trans fats, but, unfortunately, only in foods that contain at least one gram per serving. That means you could be getting some trans fats in a number of foods, which could add up to enough trans fats in a day to be unhealthy and increase cholesterol. If a food label lists "partially hydrogenated oil," it has trans fat, and it's best to avoid it.

In addition to changing your diet, making other heart-healthy lifestyle changes is key to improving your cholesterol. Exercising, quitting smoking and maintaining a healthy weight will help keep your cholesterol at a healthy level.

An avocado a day may keep bad cholesterol at bay. American Heart Association. http://blog.heart.org/avocado-day-may-help-keep-bad-cholesterol-bay/. Accessed April 27, 2015.

Wang L, et al. Effect of a moderate fat diet with and without avocados on lipoprotein particle number, size and subclasses in overweight and obese adults: A random, controlled trial. Journal of the American Heart Association. 2015;4:e00.

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